Hydraulic axial piston machine

Abstract

A hydraulic axial piston machine ( 1 ) includes a cylinder drum ( 3 ) having at least one cylinder ( 4 ) in which a piston ( 5 ) is arranged to be reciprocating, an inclined swash plate ( 8 ), on which the piston ( 5 ) is supported via a slide shoe ( 7 ), a pressure plate ( 9 ) maintaining the bearing of the slide shoe ( 7 ) on the swash plate ( 8 ), and a spring arrangement ( 10 ) by means of which the pressure plate ( 9 ) is pressed against the swash plate ( 8 ) via the cylinder drum ( 3 ). In the past, the pressure plate has been supported on the cylinder drum ( 3 ) via a ball joint, with the spring arrangement and a driving shaft for the cylinder drum penetrating the cylinder drum. The ball joint is expensive and exposed to wear. According to the invention, the spring arrangement ( 10 ) bears immediately on the pressure plate ( 9 ). Thus, a ball joint and the wear of it will be avoided.

What is claimed is:  
     
       1. Hydraulic axial piston machine comprising a rotatable cylinder drum having at least one cylinder, a piston in the cylinder arranged to be reciprocating, and an inclined swash plate on which the piston is supported via a slide shoe and further including a rotatable pressure plate maintaining the bearing of the slide shoe on the swash plate and a spring arrangement by means of which the pressure plate is pressed against the swash plate via the cylinder drum, the spring arrangement bearing immediately on the pressure plate. 
     
     
       2. Machine according to  claim 1 , in which the spring arrangement surrounds a projection of the pressure plate. 
     
     
       3. Machine according to  claim 1 , in which the spring arrangement projects into a recess in the pressure plate. 
     
     
       4. Machine according to  claim 1 , in which the spring arrangement is supported on one end of a drive shaft extending into and unrotatable in relation to the cylinder drum. 
     
     
       5. Machine according to  claim 1 , in which the spring arrangement surrounds a projection on one end of the drive shaft.